Here is the full list of all 21 Jacob Jones and the Bigfoot Mystery : Episode 1 achievements.
Complete 20 puzzles
Collect all Gnatgobblers
Complete 'That Ain't Sitting Right' in less than 13 moves
Reach the Airfield
Earn 40000 merits
Complete 'A Note of Friendship' in less than 6 moves
Meet a Bigfoot
Complete 10 Puzzles
Survive the First Night in camp
Collect 40 soda cans
Collect 3 Gnatgobblers
Complete 5 puzzles
Earn 10000 merits
Complete your first puzzle
Complete Episode 1
Earn maximum merits for Episode 1
Collect all soda cans
Complete 'Circuit Training' in less than 9 moves
Complete 'Pack Mentality' in less than 9 moves
Complete 'Rolling Blunder' in less than 27 moves
Complete 'Log Jam' in less than 12 moves